Dekker’s boat, Guppy, is still moored at its usual berth and the teenager appears to have left her father’s home on her own. “We do not believe this is a crime,” said Utrecht police spokesman Bernhard Jens.

The Dutch broadcaster NOS cited a family spokeswoman as saying that Laura left a letter for her father before disappearing. NOS did not reveal what was in the letter.

A spokeswoman for the family, Mariska Woertman, did not return calls seeking comment.